BMW M2 Radiator Fan Failure Causing Overheating Issues

Hi there! I have some experience with BMWs and had a similar issue with my 2014 M4 last summer. The symptoms you're describing sound exactly like what I went through. After noticing my engine temps climbing and the fan staying dead silent, I took it to my regular workshop. Turned out it wasn't the fan itself, but a faulty speed sensor that was preventing the fan from activating. The repair, including parts and labor, cost me around 250 Euro. Before you replace the fan, definitely have the sensor checked, could save you from unnecessary parts replacement. The speed sensor issue is actually pretty common in M-series from that generation. Could you share if you notice the problem more during idle or while driving? Also, have you scanned the check engine code? That would help narrow things down further. Let me know if you need any other info about my repair experience!

Thanks for your input! I just had my service done last month at 20094 KM, and everything was fine then. The issue started showing up mainly during idle, especially after longer drives. Haven't scanned the code yet, but I'll definitely check the speed sensor first before replacing the entire fan assembly. Really appreciate the heads up about this being a common M-series issue. Sounds like a much cheaper fix than what I was worried about!

Hey again! Thanks for the additional info. Yeah, that timing actually sounds really similar to when my issue popped up, everything was fine during regular service and then boom, problems started! The idle situation you're describing is exactly what happened with mine. After longer drives, my M4 would get pretty toasty when stopped at lights or in traffic. Since you mentioned your car's mileage, mine was around 22000 KM when this happened, so pretty close to where you're at. Just to add to my earlier response, when they fixed my sensor, they actually found some corrosion on the connector too, which was contributing to the problem. Might be worth having them check that while they're in there. The mechanic cleaned it up and applied some dielectric grease to prevent future issues. I'm glad I could help steer you away from immediately replacing the whole fan assembly! Keep us posted on what you find out after the scan. If you're getting the same error codes I got, it'll definitely confirm the sensor theory. My car's been running perfect since that repair, so hopefully you'll have the same luck!

Thanks everyone for helping out! Just wanted to update you, got the car scanned today and you were absolutely right about the speed sensor. Code matched what you mentioned, and my mechanic confirmed the same diagnosis. Even found that corroded connector you talked about! They're ordering the sensor part now and should have it fixed by tomorrow. Total quote came in at almost exactly what you paid, which is such a relief compared to what a full fan replacement would've cost. Really grateful for this community's help in saving me from unnecessarily replacing the entire fan assembly. Will definitely post another update once it's all fixed up, but feeling pretty confident this will solve the issue since our cases seem nearly identical. Thanks again for sharing your experience, it made this whole situation way less stressful!